Touch-and close fastener part

ABSTRACT

A touch-and-close fastener part, comprising a two-dimensional carrier ( 1 ), from which a main tang ( 7 ) with at least one secondary tang ( 9 ) located on it, and supporting the main tang ( 7 ) on the carrier ( 1 ), can be respectively obtained as hooking elements ( 5 ), in particular by punching or cutting, wherein the main tang ( 7 ) can be raised up about a bending line ( 13 ), which forms a first connecting region with respect to the carrier ( 1 ), into a functional position over the carrier ( 1 ), is characterized in that the at least one secondary tang ( 9 ) forms a connecting area lying against the carrier ( 1 ) and representing a further, second connecting region.

The invention relates to a touch-and-close fastener part, consisting of a two-dimensional backing from which a main tang with at least one secondary tang located thereon can be obtained as hooking elements, especially by punching or cutting, which secondary tang supports the main tang on the backing, where the main tang can be raised into a working position over the backing around a bending line which forms a first connecting region to the backing.

A touch-and-close fastener part of this type has already been disclosed in DE 44 41 095 C2. Due to the secondary tangs which help to increase the structural strength of the main tangs which on their end regions form the actual mushroom-shaped or hook-shaped hooking elements, these touch-and-close fastener parts are suitable for producing touch-and-close fasteners which are suited for demanding operating conditions, for example, for anchoring grinding wheels or coarse fiber nonwovens in grinding machines, or floor care implements. These touch-and-close fasteners produced on a plastic basis cannot, however, be used in those applications in which, in addition to high mechanical loads, there are also thermal loads, due to the lack of temperature stability. In order to exploit the advantages of proven plastic-based touch-and-close fastener systems, as are most common for a plurality of applications, even in those applications in which plastic touch-and-close fasteners cannot be used, it is prior art, compare DE 10 2006 015 145 A1, to form a type of metal touch-and-close fastener by the hooking elements being cut out from a metal backing, for example, a heat-resistant metal alloy such as high-grade steel, and raised. These fastening systems enable prompt and simple installation of third components without the need for additional holding devices and their actuation by special tools. Special demands must, however, be imposed on the operating behavior of these fastening systems; in particular, a relatively large holding force must be present to secure the pertinent parts against static or dynamic (oscillations) load forces which may occur.

In this respect, the object of the invention is to make available a touch-and-close fastener part which has hooking elements consisting of main tangs and secondary tangs, in which especially strong and reliable anchoring of the hooking elements on the backing is ensured.

This object is achieved according to the invention by a touch-and-close fastener part having the features of claim 1 in its entirety.

Accordingly, one important feature of the invention consists in that the at least one secondary tang located on the respective main tang is made and arranged such that it forms a connecting surface which adjoins the backing and by which another second connecting region is formed on the backing. This two-dimensional linking of the hooking elements to the backing and the resulting increase of structural strength make these touch-and-close fastener parts suitable for applications in which large adhesive forces and high resistivity are necessary.

In particular, these touch-and-close fastener parts are suitable for implementation of metal touch-and-close fasteners which are intended for applications in which high mechanical and/or thermal loads occur.

In especially advantageous exemplary embodiments, the main tang on its foot part adjoining the backing has a pair of secondary tangs in the form of one strip-like extension at a time which adjoins either side edge of the foot part. In this way the connecting surfaces are laterally offset relative to one another and are thus especially suitable for delivering into the backing the forces produced by bending moments.

Preferably the arrangement is made such that the foot part widens toward the bending line with side edges which run diverging to one another, around which line it is raised out of the backing plane, with the extensions which form the secondary tangs being formed by notches in the backing which border the bending line on both sides and which form projections of the diverging side edges.

In this arrangement of the extensions, they can be displaced to under the backing around second bending lines which laterally adjoin the ends of the bending line of the foot part, can be guided along the bottom of the backing up to an opening in the backing, and can be displaced up onto the backing on third bending lines through the opening in the backing. In this way an overall connecting surface is created that consists of the contact surface located underneath the backing plus the contact surface on the top of the backing by the end sections of the extensions, which sections are displaced onto the backing.

In alternative exemplary embodiments in which the connecting surfaces between the extensions which form the secondary tangs and the backing are located entirely on its underside, the arrangement is made such that the sections of the secondary tangs adjoining the underside of the backing are overlapped by an assigned auxiliary tang which has been cut out of the backing, and are kept in contact with the underside of the backing.

In this respect, the arrangement can be made such that the auxiliary tangs are formed by cutouts of the backing such that the cut-out auxiliary tangs can be displaced around fourth bending lines which extend along the end edges of the secondary tangs which adjoin the underside of the backing and can be placed on the secondary tangs.

In the production of the touch-and-close fastener part according to the invention, the main tangs with the foot part and the secondary tangs can be formed by a single cutout of the backing with a single cutting line which is uninterrupted except for the connecting site to the backing which forms the bending line on the foot part. This enables simple and efficient production in which, prior to bending processes which are carried out for raising and displacing the tang parts, simply a single cutting or punching step is necessary to form the main and secondary tangs, optionally combined with a cutting or punching process for forming the auxiliary tangs.

As already mentioned, the touch-and-close fastener part according to the invention is especially suited for forming a metal touch-and-close fastener, with a suitable metal backing being provided, for example, a steel sheet of steel alloy which is suitable for the intended application.

In especially advantageous exemplary embodiments, on the connecting surfaces there are connecting sites, for example, by cementing or spot welding, preferably these connecting sites also being provided between auxiliary tangs and the regions of the secondary tangs covered by them.

The invention is detailed below using the exemplary embodiments shown in the drawings.

FIG. 1 shows a perspective oblique view of only one partial section of the backing with a single hooking element, consisting of a main tang and a pair of secondary tangs according to a first exemplary embodiment of the invention, which view is shown greatly enlarged to illustrate the operating principle of the invention, with the end section of the secondary tang shown in the figure not yet being displaced to the final degree;

FIG. 2 shows an oblique view corresponding to FIG. 1, with the visible secondary tang being shown in the ultimately displaced position;

FIG. 3 shows a plan view of a backing section, less dramatically enlarged compared to FIGS. 1 and 2, with cutting lines for forming a hooking element of a second exemplary embodiment of the touch-and-close fastener part according to the invention;

FIGS. 3 a to 3 l show in a perspective oblique view schematics of successive working steps of production of the second exemplary embodiment; and

FIG. 4 shows a perspective oblique view of the backing section, enlarged accordingly, with the completed hooking element of the touch-and-close fastener part of the second exemplary embodiment.

The invention is detailed below using exemplary embodiments in which the touch-and-close fastener part is designed to form a metal touch-and-close fastener, and, accordingly, there is a metal backing 1. Depending on the intended application, it can be a steel sheet, made, for example, of a highly heat-resistant, high-grade steel alloy, the sheet thicknesses being chosen accordingly, for example in a range from 0.1 to 2 mm. Cutting or punching with a cutting line 3 forms the outline of the hooking elements 5, which each consist of a main tang 7 and a pair of secondary tangs 9 which are integrally joined to the main tang 7, of which secondary tangs FIGS. 1 and 2 show only one, while the second secondary tang 9 in the direction of looking at FIGS. 1 and 2 is concealed by the foot part 11 of the main tang 7, which part is widened toward the bottom and forms a partial triangle. This foot part 11 is connected to the backing 1 by way of a straight bending line 13 around which the main tang 7 is raised out of the plane of the backing 1. As is apparent from FIGS. 1 and 2, to form the main tangs 7 and secondary tangs 9, only a single cutting line 3 is necessary which runs without interruption as far as the ends of the bending line 13; i.e., it is interrupted solely by the bending line 13. The upper head part 15 is made in the form of mushroom head in order to be used as an effective anchoring part of the formed hooking element 5.

The secondary tangs 9 are formed by extensions which adjoin the foot part 11 on the two side edges 17, and they are formed by notches 19 of the backing 1 which have the shape of a partial rectangle whose one longitudinal side at a time forms a prolongation of the bordering side edge 17 of the foot part 11. The notches 19 are closed by second bending lines 21, which each form lateral prolongations of the bending line 13 on which the foot part 11 is joined to the backing 1. As FIGS. 1 and 2 show, the secondary tangs 9 are displaced around the second bending line 21 under the underside of the backing 1 and are guided on the underside of the backing 1 up to a slot-shaped opening 23 through which the respective end parts 25 of the secondary tangs 9 are inserted toward the top. FIG. 1 shows the state in which the end parts 25, though inserted through the openings 23, are not yet displaced onto the top of the backing 1 around a third bending line 27 which is located on the opening 23. FIG. 2 shows this finished state, where the end parts 25 of the secondary tangs 9 rest on the top of the backing 1.

As is apparent, the secondary tangs. 9 form large-area connecting surfaces for anchoring the main tang 7 on the backing 1. Because the notches 19 and thus the resulting secondary tangs 9 which are formed thereby run divergently, the latter are spread to the sides relative to the central region of the foot part 11 so that support and anchoring take place laterally outside of the cutting line 3 and therefore in a region of the backing 1 that is favorable for delivery of the load forces. On the connecting surfaces to the backing 1, i.e., along the secondary tangs 9 underneath the backing 1 and between the end parts 25 and the top of the backing 1, there are connecting sites by spot welding or cementing.

FIGS. 3 and 4 show a modified exemplary embodiment. As is best shown in FIGS. 3 and 3 a, in the backing 1 outside the cutting line 3, which forms the main tang 7 and the pair of secondary tangs 9 and which is uninterrupted except for the bending line 13 on the foot part 11, there are additional cutting lines 29 which delineate the cutouts 31 which are joined to the backing 1 on the fourth bending lines 33. These cutouts 31 are used to form auxiliary tangs 35, see FIG. 3 d. This FIG. 3 d shows the backing 1, viewed on its underside 37. Here a state is shown in which the secondary tangs 9 are displaced first around the bending lines 21 such that they stand up on the underside 37 of the backing 1. Likewise, FIG. 3 d shows that around the bending lines 33 the auxiliary tangs 35 are also raised on the underside 37 of the backing 1, but are not yet displaced. Proceeding from the state of FIG. 3 a, this is done by the sequence of production steps of FIGS. 3 a, 3 b, and 3 c, specifically in the interaction of a hold-down device 39 and dies 41, 43, 45, and 47, see FIGS. 3 a to 3 c, each likewise looking at the bottom 37 of the backing 1.

FIGS. 3 e to 3 g, in the direction of looking likewise at the underside 37 of the backing 1, show the raising of the main tang 7 from the top 49 of the backing 1 which is visible in FIG. 4. This takes place, see FIGS. 3 e to 3 g, by means of a beveled die 51 and counterstay 53, proceeding from the state of FIGS. 3 e and 3 f with both the main tang 7 being bent around the bending line 13 and also the auxiliary tangs 9 being placed around their bending lines 21 on the underside 37 of the backing 1, since the secondary tangs 9 are entrained by the pivoting motion of the main tang 7. FIG. 3 h shows the state in which the secondary tangs 9 adjoin the underside 37 of the backing, but the auxiliary tangs 35 have not yet been displaced around their bending lines 33 and are placed above the secondary tangs 9. This takes place as shown in FIGS. 3 i to 3 k by means of dies 55, as a result of which the finished state shown in FIG. 31 is obtained in which, however, the underside 37 of the completed touch-and-close fastener part can be seen. Conversely, FIG. 4 likewise shows the completed state, where, however, the top 49 of the backing 1 is visible. As a comparison of FIGS. 3 l and 4 best illustrates, in the exemplary embodiment of FIGS. 3 and 4, all connecting surfaces are located between the secondary tangs 9 and the backing 1 on its underside 37, where the secondary tangs 9 adjoin along the underside 37 and are overlapped by the auxiliary tangs 35. In contrast, in the exemplary embodiment as shown in FIGS. 1 and 2 there are connecting surfaces on the bottom 37 and top 49 of the backing 1, specifically by the sections of the secondary tangs running along the underside 37 and their end parts 25 which have been displaced through the openings 23 upward onto the top 49. As already mentioned, on all connecting surfaces there are connecting sites, as also between the auxiliary tangs 35 and secondary tangs 9. 

1. A touch-and-close fastener part, consisting of a two-dimensional backing (1) from which a main tang (7) with at least one secondary tang (9) located thereon can be obtained as hooking elements (5), especially by punching or cutting, which secondary tang supports the main tang (7) on the backing (1), where the main tang (7) can be raised into a working position over the backing (1) around a bending line (13) which forms a first connecting region to the backing (1), characterized in that the at least one secondary tang (9) forms a connecting surface which adjoins the backing (1) and which represents another second connecting region.
 2. The touch-and-close fastener part according to claim 1, characterized in that the main tang (7) on its foot part (11) adjoining the backing (1) has a pair of secondary tangs in the form of one strip-like extension at a time which adjoins either side edge (17) of the foot part (11).
 3. The touch-and-close fastener part according to claim 2, characterized in that the foot part (11) with side edges (17) which run divergently to one another widens toward the bending line (13) around which it is raised out of the plane of the backing, and that the extensions which form the secondary tangs (9) are formed by notches (19) in the backing (1) which border the bending line (13) on both sides and which form projections of the diverging side edges (17).
 4. The touch-and-close fastener part according to claim 3, characterized in that the extensions which form the secondary tangs (9) for forming the enlarged connecting surfaces on the backing (1) are guided along the underside (37) of the backing (1) as far as the opening (23) of the backing (1) around second bending lines (21) which laterally adjoin the ends of the bending line (13) of the foot part (11), displaced to under the backing (1), and are displaced up onto the backing (1) on third bending lines (27) through the opening (23) in the backing (1).
 5. The touch-and-close fastener part according to claim 4, characterized in that the sections of the secondary tangs (9) adjoining the underside (37) of the backing (1) are overlapped by an assigned auxiliary tang (35) which has been cut out of the backing (1) and are kept in contact with the underside (37) of the backing (1).
 6. The touch-and-close fastener part according to claim 5, characterized in that the auxiliary tangs (35) are formed by cutouts (31) of the backing (1) such that the cut-out auxiliary tangs (35) can be displaced around fourth bending lines (33) which extend along the end edges of the secondary tangs (9) which adjoin the underside (37) of the backing (1) and can be placed on the secondary tangs (9).
 7. The touch-and-close fastener part according to claim 1, characterized in that the main tangs (7) with the foot part (11) and the secondary tangs (9) are formed by a single cutout of the backing (1) with a single cutting line (3) which is uninterrupted as far as the connecting site to the backing (1), which site forms the bending line (13) on the foot part (11).
 8. The touch-and-close fastener part according to claim 1, characterized in that it has a metal backing (1) for forming a metal touch-and-close fastener.
 9. The touch-and-close fastener part according to claim 4, characterized in that connecting sites are formed, especially by cementing or spot welding, on the connecting surfaces.
 10. The touch-and-close fastener part according to claim 9, characterized in that the connecting sites are formed between auxiliary tangs (35) and the regions of the secondary tangs (9) covered by them. 